Treatment of venous thromboembolism in cancer patients

Low-Molecular-Weight Heparin Versus Warfarin in Adult Cancer Patients as a Precision Medicine for Thrombosis: A Systematic Review and Meta-Analysis

Venous thromboembolism (VTE) is a condition often seen in patients diagnosed with cancer and is recognized as a predictor of poor outcomes in these patients. The probability of VTE recurring is generally higher in people with cancer than in those without; hence, addressing this issue is essential when making healthcare decisions. Therefore, our systematic review was primarily designed to compare low-weight- molecular heparin (LMWH) to warfarin in reducing recurrent VTE among cancer patients. However, other outcomes were also evaluated, such as mortality and bleeding events observed more in cancer patients. The selection of relevant articles was carried out using a database search and a manual search, which involved reviewing reference lists of articles eligible for inclusion in the current review. The methodological quality of each included study was then assessed using Cochrane's risk of bias tool in the Review Manager software (RevMan 5.4.1). Additionally, pooled results were examined using the Review Manager software and presented as forest plots. Our search of electronic databases elicited a total of 2163 articles, of which only six were deemed eligible for inclusion and analysis. Data pooled from the six studies demonstrated the effectiveness of LMWH in minimizing the reoccurrence of VTE over warfarin [risk ratio (RR): 0.67; 95% CI: 0.47 - 0.95; p = 0.03]. However, LMWH had a similar effect statistically as warfarin on the major bleeding events (RR: 1.05; 95% CI: 0.62 - 1.77; p = 0.85), minor bleeding events (RR: 0.80; 95% CI: 0.54 - 1.20; p = 0.28), and all-cause mortality (RR: 1.00; 95% CI: 0.88 - 1.13; p = 0.99). While LMWH demonstrated its effectiveness in minimizing the incidence of VTE recurrence over warfarin in cancer patients, it had no statistical difference in terms of mortality or bleeding events when compared to warfarin. Based on our findings, we recommend that LMWH continues to be used as a first-line treatment regimen to mitigate recurrent VTE in cancer patients.

Totally Implantable Ports Connected to Valved Catheters for Chemotherapy: Experience from 350 Groshong Devices

Purpose

There are few studies regarding the use of totally implantable valved ports for chemotherapy. The objective of this study was to analyze the results obtained from consecutive implantation of 350 devices.

Methods

Adult patients submitted to port insertion in veins of the superior vena cava system over a 17-month period (July 2006 to December 2007) were considered. The device used was composed of a titanium and silicone rubber port (Dome Port™; Bard Inc, Salt Lake City, UT) connected to an 8.0 Fr silastic Groshong™ catheter tube. Follow-up was conducted on outpatient data and during clinical readmissions, until the device was removed or the patient died.

Results

Three hundred and fifty devices, total of 74,691 days in situ, were inserted, with a median follow-up of 176 days. There were 11 early complications (3.1%) and 49 late complications (14%), 21 of these (6%) were considered major ones. Early complications comprised four instances of phlebitis of the external jugular, three of pocket infection, two of technical failure and two of ecchymosis. Late complications comprised 33 instances of withdrawal difficulty, 12 of port-related bacteremia, two of deep venous thrombosis, one of occlusion and one of catheter fracture. Out of the 350 catheters implanted, 258 (73.5%) were still being used, 73 (21%) remained in use until the patient died, five (1.5%) were removed at the end of the treatment and 14 (4%) were removed because of complications.

Conclusions

There was a low rate of major complications associated with this valved system justifying its use.

Cancer-associated thrombosis

Thrombosis is a common complication in patients with cancer and it is estimated that about 20% of patients with cancer experience venous thromboembolism (VTE). This complication is associated with high rate of morbidity and mortality and is sometimes the first manifestation of an occult cancer. The risk profiles and markers involved in cancerassociated thrombosis share similarities with inflammation-induced atherosclerosis and thrombosis. The type of cancer, chemotherapy, surgery, central venous catheters, pre-chemotherapy platelet and leukocyte count are associated with high risk of VTE in cancer patients. Landmark studies demonstrated that effective prophylaxis and treatment of VTE reduced morbidity and increased survival. Low-molecular-weight heparin (LMWH) is preferred as an effective and safe means for prophylaxis and treatment of VTE. It has largely replaced unfractionated heparin and vitamin K antagonists. The advantages of LMWH include increased survival and quality of life, decreased rate of VTE, low incidence of thrombocytopenia. New guidelines for prophylaxis and treatment are now available and prophylaxis is recommended in hospitalized cancer patients and patients undergoing major surgery. Treatment with LMWH should be considered as the first line of therapy for established VTE and to prevent recurrent thrombosis in patients with cancer.

Venous thromboembolism prevention in cancer patients: the search for common antecedents

Venous thromboembolism (VTE) is a well-recognized concomitant of cancer. Although treatment with warfarin is often difficult and tedious, the heparins, and particularly the low molecular weight heparins, have afforded improved care of the patient with cancer-associated VTE, but with increased cost and the need for self-injection. Development by the pharmaceutical industry of inhibitors of specific activated coagulation factors and P-selectin holds promise for improved control of thrombosis with reduced toxicity. Increasing understanding of the interplay between the coagulation mechanism and neoplasia has yielded clues to the upstream origins of both, which may lead to experimental intervention potentially capable of preventing both.

Low-molecular-weight heparins in the treatment of cancer-associated thrombosis: a new standard of care?

Cancer patients are twice as likely to develop postoperative venous thromboembolism (VTE) than non-cancer patients undergoing the same surgical procedure. Causes of cancer-associated thrombosis include: the capacity of tumor cells and their products to interact with platelets, clotting, and fibrinolytic proteins. Aggressive antitumor therapy with agents such as platinum compounds, high-dose fluorouracil, mitomycin-C, tamoxifen, and growth factors increase the risk of cancer-associated thrombosis. Despite the high risk of VTE in patients with cancer, thromboprophylaxis in surgical and medical oncology patients is low. Initial therapy of VTE in patients with cancer is low-molecular-weight heparin (LMWH) or unfractionated heparin. Long-term secondary prophylaxis of VTE is generally accomplished with oral anticoagulants, primarily warfarin. Evidence supports the use of LMWH for prevention and treatment of cancer-associated thrombosis because it is more easily administered, does not require laboratory monitoring, has a lower risk of adverse events, and is more cost effective than unfractionated heparin. In addition, the antineoplastic effects of LMWH have been demonstrated, including direct antitumor, antiangiogenic, and immune system modulatory action. Each LMWH is a unique biological entity having product-specific molecular and structural attributes; therefore, different LMWHs cannot be given interchangeably. Continued investigation of LMWH therapy in patients with cancer is warranted.

Therapeutic Options for the Treatment of Cancer-Associated Thrombosis

OBJECTIVE

To provide oncology nurses with an understanding of therapeutic options for cancer-associated thrombosis, strategies to prevent recurrence, and practical issues in patient management.

DATA SOURCES

Primary and tertiary literature and the author's clinical experience.

CONCLUSION

Oncology nurses monitor patients throughout the care continuum for signs and symptoms indicating vascular thromboembolism and need to know the steps to take to expedite an accurate diagnosis and ensure prompt treatment.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses must keep informed about the evolving evidence that leads to practice changes. They should be able to teach patients about therapeutic options and their potential for improving outcomes.

Home therapy for deep vein thrombosis and pulmonary embolism in cancer patients

Outpatient treatment of deep vein thrombosis (DVT) has become a common practice in uncomplicated patients. Few data are still present in patients with comorbidity (such as cancer) or concomitant symptomatic pulmonary embolism. Cancer patients with DVT are often excluded from home treatment because they have a higher risk of both bleeding and recurrent DVT. We tested the feasibility and safety of the Home Treatment (HT) program for acute DVT a PE in cancer patients. Patients were treated as outpatients unless they required admission for other medical problems, were actively bleeding or had pain that requires parenteral narcotics. Outpatient treatment was with low molecular weight heparin (LMWH) followed by warfarin or with LMWH alone. An educational program for patients was implemented. Two-hundred and seven patients with cancer were evaluated, 36 (17.4%) of whom had metastatic disease. Treatment with LMWH and warfarin was prescribed to 106 (51.2%) and LMWH alone to 102 (48.8%). One hundred and twenty-seven patients (61.3%) were entirely treated at home. There were no differences between patients treated at home and hospitalized patients with regard to gender, mean age, site of cancer, presence of metastases, and treatment. After 6 months, recurrent thrombo-embolism occurred in 8.7% of patients treated at home and in 5.6% of hospitalized patients (P=0.58); major bleeding in 2.0% and 1.5%, respectively (P=0.06). Twenty-seven patients (33%) in the hospitalized, and 33 (26%) in the home-treatment group, died after a follow-up of 6 months. These results indicate that, regarding cancer patients with acute DVT and/or PE, there is no difference between hospitalised and home-treated patients in terms of major outcomes.

Warfarin versus low-molecular-weight heparin therapy in cancer patients

The association between cancer and venous thromboembolism (VTE) is well established. Importantly, VTE is a significant cause of mortality in cancer patients. Although long-term warfarin (Coumadin(trade mark); Bristol-Myers Squibb; New York, NY) therapy is the mainstay of treatment for cancer patients with VTE, there are many practical problems with its use in this population. In particular, achieving therapeutic drug levels is difficult in cancer patients due to the increased risk of drug interactions, malnutrition, vomiting, and liver dysfunction in these patients. Moreover, cancer patients are at an increased risk of adverse effects of warfarin therapy. In contrast, low-molecular-weight heparins (LMWHs) are associated with a lower risk of adverse events compared with warfarin in patients with cancer. These agents also offer practical advantages compared with warfarin, including more predictable anticoagulant effects and ease of administration in addition to possible antineoplastic effects. Several LMWHs have demonstrated superior efficacy to warfarin in the secondary prevention of VTE. In particular, the LMWH, dalteparin (Fragmin; Pfizer; New York, NY), has recently been shown to have superior efficacy to warfarin in a large trial of patients with cancer and VTE without increasing the risk of bleeding. A randomized trial of dalteparin has also shown improved response rates and survival in patients with small cell lung cancer. In view of the availability of more effective and reliable alternatives to warfarin therapy in cancer patients, it is appropriate to reassess the role of warfarin therapy in patients with cancer and VTE. Further evaluation of the LMWHs for effects on cancer outcome is indicated.

Traitement de la maladie thromboembolique veineuse chez les patients souffrant de cancers

PURPOSE

Venous tromboembolic treatment in patients with cancer can be a clinical dilemma. Comorbid conditions, significant risk of recurrence of bleeding associated with warfarin, difficult venous access, are some of the factors that often complicate anticoagulants therapy in patients with cancer.

EXEGESIS

Low molecular weight heparin has replaced unfractionated heparin as the first line treatment in the majority of patients with venous thromboembolism and cancer, in hospital or safely at home. Recent trial demonstrated that long-term low molecular weight heparin administrated over a 6-month period reduced the rate of recurrence venous thromboembolism with non increase in bleeding compared with oral anticoagulant therapy. Placement of an inferior vena caval filter should be reserved for patients with active or very high risk of bleeding, but oncologist should consider these sobering results in such patients. Whether anticoagulants might also improve cancer survival rates independent of their effect on thromboembolism deserves further investigation.

PERSPECTIVE

In future, new antithrombotic agents such as oral direct thrombin or long-acting synthetic factor Xa inhibitor may be useful in these patients.